diff options
| author |   Sven Schnelle <svens@stackframe.org> | 2019-06-05 22:32:18 +0200 |
|---|---|---|
| committer |   Helge Deller <deller@gmx.de> | 2019-06-08 12:56:26 +0200 |
| commit | 7e923369b1ec92af5f048d2146b44f9132abe1ad (patch) | |
| tree | e1ebdd4596415f23e2b008c9e5e6642b4b6995e1 /arch/parisc | |
| parent | parisc: add support for patching multiple words (diff) | |
| download | linux-dev-7e923369b1ec92af5f048d2146b44f9132abe1ad.tar.xz linux-dev-7e923369b1ec92af5f048d2146b44f9132abe1ad.zip | |
parisc: add spinlock to patch function
If multiple CPUs are patching code we need the spinlock
to protect against parallel fixmap maps/unmap calls.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Diffstat (limited to 'arch/parisc')
| -rw-r--r-- | arch/parisc/kernel/patch.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/arch/parisc/kernel/patch.c b/arch/parisc/kernel/patch.c index 70e9997a3f80..80a0ab372802 100644 --- a/arch/parisc/kernel/patch.c +++ b/arch/parisc/kernel/patch.c @@ -23,7 +23,9 @@ struct patch { static DEFINE_RAW_SPINLOCK(patch_lock); -static void __kprobes *patch_map(void *addr, int fixmap, int *need_unmap) +static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags, + int *need_unmap) +{ unsigned long uintaddr = (uintptr_t) addr; bool module = !core_kernel_text(uintaddr); struct page *page; @@ -38,19 +40,29 @@ static void __kprobes *patch_map(void *addr, int fixmap, int *need_unmap) *need_unmap = 1; set_fixmap(fixmap, page_to_phys(page)); + if (flags) + raw_spin_lock_irqsave(&patch_lock, *flags); + else + __acquire(&patch_lock); return (void *) (__fix_to_virt(fixmap) + (uintaddr & ~PAGE_MASK)); } -static void __kprobes patch_unmap(int fixmap) +static void __kprobes patch_unmap(int fixmap, unsigned long *flags) { clear_fixmap(fixmap); + + if (flags) + raw_spin_unlock_irqrestore(&patch_lock, *flags); + else + __release(&patch_lock); } void __kprobes __patch_text_multiple(void *addr, u32 *insn, unsigned int len) { unsigned long start = (unsigned long)addr; unsigned long end = (unsigned long)addr + len; + unsigned long flags; u32 *p, *fixmap; int mapped; @@ -58,7 +70,7 @@ void __kprobes __patch_text_multiple(void *addr, u32 *insn, unsigned int len) flush_kernel_vmap_range(addr, len); flush_icache_range(start, end); - p = fixmap = patch_map(addr, FIX_TEXT_POKE0, &mapped); + p = fixmap = patch_map(addr, FIX_TEXT_POKE0, &flags, &mapped); while (len >= 4) { *p++ = *insn++; @@ -72,14 +84,15 @@ void __kprobes __patch_text_multiple(void *addr, u32 *insn, unsigned int len) flush_kernel_vmap_range((void *)fixmap, (p-fixmap) * sizeof(*p)); if (mapped) - patch_unmap(FIX_TEXT_POKE0); - p = fixmap = patch_map(addr, FIX_TEXT_POKE0, &mapped); + patch_unmap(FIX_TEXT_POKE0, &flags); + p = fixmap = patch_map(addr, FIX_TEXT_POKE0, &flags, + &mapped); } } flush_kernel_vmap_range((void *)fixmap, (p-fixmap) * sizeof(*p)); if (mapped) - patch_unmap(FIX_TEXT_POKE0); + patch_unmap(FIX_TEXT_POKE0, &flags); flush_icache_range(start, end); } |